In the prior art, shore protection works attempted to prevent erosion of the end of the slope and foundation movement by waves by covering the front of the slope with npraps and concrete blocks. Likewise, foot protection of the end of the slope was included to prevent the progress of foundation movement or erosion. For foot protection, many methods of constructions are used, for instance, the form shown in the Japanese patent applications 04359388 and 06164640 may be used. Hollow framing is typically formed by using wire netting and the cage frame is filled with stones, and/or broken stones, on the inside.
However, cage frames made by wire netting have several disadvantages. First, because the hollow framing is made by wire netting, it does not have sufficient strength. When the broken stones are added for filling, the wire netting is typically deformed by being not able to handle the weight of those, and it has a chance to be deformed by the force of water, such as during flooding. At these situations, the framing can not properly function as a cage frame for shore protection and the like because the broken stones would flow out. Second, because the wire netting is made with mild steel which has low carbon, it is easy to corrode. When part of wire netting is broken by slow deterioration, the cage frame function is defeated when the broken stones, stones and so on flow out from the broken part. Further, because the hollow framing is made by wire netting, bacteria which like carbon do not stick to the surface, so it cannot be used efficiently as a gathering place for fish.
Third, the hollow framing is constructed by joining many face materials, and for the joint, the string type material is used, the string type material is easily corroded and has a chance to be broken. If the string material is broken, the hollow framing will be apart, broken stones and stones will flow outside, then it can not properly function as the cage frame.
The purpose of this invention is because of these situations and to provide the cage frame for shore protection and so on which can have greatly improved durability, can be easily set up and executed at the site, can easily create appropriate environment for organism's habitat, and can be used efficiently as a gathering place for fish.